Knife for leather-skiving machines.



0. A. HIRTH. KNIFE FOR LEATHER SKIVING MACHINES. APPLICATION FILED APR.2D, 1911.

1,117,381, Patented Nov. 17, 1914.

, CARL ALBERT HIIRTH, OI" CAtNNSTAT'l, STUTTGART, GERMANY.

KNIFE FOR LEATHER-SKIVING MACHINES.

'1 '0 al 107mm it may concern lie it known that 1, (ant ALnnirr liin'rn, a subject of the German Eniperor, residing at tannstatt, Stuttgart, Germany, have in vented a certain new and useful Improved Knife for lieathenfikiving lilachines, of which the following is a speciti'ration.

This invention relates to an improved knife for leather skiving and like machines of the cylindrical type which is used in leather skiving, heveling, and splitting machines.

'lhe iiresent invention has for its object to produce a. cutting knife of a simple character possessing great resistance and cutting power and an iinweased working life. while at the same time it is specially formed so as to insure its being truly mounted upon the carrier shaft both as regards being at right angles thereto and central thereon. so that it will revolve with a perfectly true running cutting edge.

To this end the improved knife is formed so that it l is in combination two features, viz:-l t is formed out of one piece of material. that is to say, the cylindrical portion, which has inner and "outer concentric cylindrical walls for a part of its length. and the end disk, which is thicker than the ey lindrical portion between said inner and outer walls, are formed integrally of one and the same piece of metal. which is turned, hardened, ground and finished and consequently must retain its form, having no internal strains, the front or edge of the overhanging rim of the cylindrical portion being sharpened in the usual manne and on the disk or flattened portion of the knife a central hole is made and a raised surface is provided into which a series of holes are pierced to enable the knife to be fastened to the end of the shaft in the skiving ma chine in a manner which is usual.

l'teferring to the annexed drawing, which is section through the center of the knife, c is the cutting edge, 71 the cylindrical or overhanging rim or surface provided for wear, a is the thickened disk on which is a raised surface (1 ground truly at right angles to the cylindrical portion of the knife and (Z is the central hole also ground truly to insure the knife being mounted centrally on the (airrying shaft.

ilt will be seen from the foregoing and Specification of Letters Patent.

Application filed April 29, 1911.

Patented Nov. 17, 191%.

Serial No. 024,213.

with re l'crenee to the drawing that the great resistance and extreme lightness of the knife is caused by the cvlindrical portion 7) being connected to the disk portion a through the rounding of the metal connecting the disk to the cylindt' and it will also be clear for the same reason that the cylindrical portion may be of considerably increased length, giving approximately one-fifth longer life than a. knife of the usual lengthand construction. while at the same time the knife may he mounted on its shaft with great accuracy seeing that the ground hole (Z will lit upon the shaft to exactly centralize the knife. and the ground raised surface e by being; firmly bolted or screwed up to the flange or shoulder on the shaft through the holcs'jQu'ill keep the knife at right angles to the shaft.

"i am aware that it is not new to form a cutting knife. of the kind herein described, out of one piece of material, and I do not claim this feature except in combination with the other herein described features for truly mounting the knife upon its shaft, and further. I am aware that similar ,means to the last mentioned features for truly mounting the kni fc have been provided on similar cutting kniv'es. but such knives have not been made in one piece of matcriah What I claim is:-

The herein described knife for a leather skiving machine comprising a body of cylindrical form in cross section having inner and outer concentric cylindrical 'alls with a cutting edge at one end. and provided at its other end with an integral head of greater thickness throughout than the body, said head having a central portion of increased thickness with parallel valls pr0- vided with an aperture concentric with the knife body to receive a support for the knife, and accurately center the knife on such support, and a plurality of apertures f to receive fastening devices for securing the knife to its support.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

t iiltl i ALBERT HIRTll.

llitnesses:

Rimes-r l ln'rimiuaar:

Fania .Kmmnn. 

